- Windows 11 26H2 Installation Assistant now refuses upgrades from 24H2 and 25H2 because they can use an enablement package.
- A hands-on test confirmed the tool blocks a 25H2 upgrade but allows an upgrade from Windows 11 23H2.
- Supported Windows 10 and older Windows 11 installations can still use the Installation Assistant to upgrade to 26H2.
- Windows Update or an enablement package is the appropriate upgrade path for supported 24H2 and 25H2 PCs.
Microsoft has changed how the Windows 11 Installation Assistant works with version 26H2. The tool now refuses to upgrade computers running Windows 11 version 24H2 or 25H2 because those installations can move to the 2026 Update through an enablement package instead of a full feature update installation.
I manually tested the change by attempting to upgrade a computer running Windows 11 25H2 to version 26H2 using the Installation Assistant. The tool wouldn’t proceed and instead displayed the message, This device is already running the latest version of Windows 11
.
I then set up another computer with Windows 11 23H2 and tested the same Installation Assistant. In this case, the tool let the upgrade proceed to Windows 11 26H2.
This difference confirms that Microsoft now treats these two upgrade scenarios differently. Computers running 24H2 or 25H2 don’t need the full Installation Assistant process because Windows 11 26H2 can be enabled through a smaller enablement package. Older installations, such as 23H2, still require a traditional feature update to reach the latest release.
Installation Assistant no longer applies to 24H2 and 25H2
The Installation Assistant has traditionally provided another way to install a new version of Windows 11 when Windows Update doesn’t offer a feature update. However, using the tool involves a much more extensive upgrade process than installing an enablement package.
Windows 11 24H2, 25H2, and 26H2 share the same underlying platform. As a result, Microsoft can deliver 26H2 to supported 24H2 and 25H2 computers through an enablement package that activates the newer release rather than performing a full operating system upgrade.
Microsoft now prevents the Installation Assistant from being used for these installations. When the tool detects Windows 11 24H2 or 25H2, it displays:
This device is already running the latest version of Windows 11.
The message may seem incorrect at first because Windows 11 26H2 is newer. However, the message indicates that the current installation doesn’t require a full upgrade through the Installation Assistant.
Older Windows versions can still use the tool
The change doesn’t make the Installation Assistant obsolete.
My test with Windows 11 23H2 showed the tool still works when moving from an older Windows 11 release to version 26H2. Microsoft also provides the tool for supported Windows 10 installations that meet the Windows 11 requirements.
This distinction is important to note because older releases don’t have the same enablement-package upgrade path as 24H2 and 25H2. For example, a supported device running Windows 10 can use the Installation Assistant to move to Windows 11 26H2. A computer running Windows 11 23H2 can also use the tool to perform the upgrade.
Meanwhile, computers already running Windows 11 24H2 or 25H2 should use Windows Update or the appropriate enablement package to move to 26H2.
Microsoft is preventing an unnecessary reinstall
This is a relatively small change, but it could keep users on a more complicated upgrade path than necessary.
Have you tried using Installation Assistant to upgrade to Windows 11 26H2?
Voting closes: October 10, 2026 1:12 pm
A user running Windows 11 25H2 might have previously assumed the Installation Assistant was the right tool to manually force the 26H2 upgrade. However, because 25H2 can move to 26H2 through an enablement package, a full Installation Assistant upgrade isn’t necessary.
The new behavior better aligns the tool with Microsoft’s servicing model. If a computer needs a full feature upgrade, the Installation Assistant can handle it. If the computer is already running a version that can move to 26H2 through an enablement package, the tool won’t attempt the unnecessary installation.
For users, the important point is that the Installation Assistant refusing to upgrade 24H2 or 25H2 doesn’t mean the computer cannot run Windows 11 26H2. It simply means the full Installation Assistant process isn’t required.
Windows Update remains the recommended way to get version 26H2, while the enablement package offers another option for supported 24H2 and 25H2 installations when the update doesn’t appear automatically.
Microsoft made the Windows 11 26H2 Installation Assistant available on September 29, 2026, alongside the rollout of the Windows 11 2026 Update.
Mauro Huculak is a Windows How-To Expert and founder of Pureinfotech in 2010. With over 23 years as a technology writer and IT Specialist, Mauro specializes in Windows, software, and cross-platform systems such as Linux, Android, and macOS.
Certifications: Microsoft Certified Solutions Associate (MCSA), Cisco Certified Network Professional (CCNP), VMware Certified Professional (VCP), and CompTIA A+ and Network+.
Mauro is a recognized Microsoft MVP and has also been a long-time contributor to Windows Central.
You can follow him on YouTube, Threads, BlueSky, X (Twitter), LinkedIn and About.me. Email him at [email protected].
